Artillery trainer



Dec 15, 1942. H. E. MIVKKELSEN ARTILLERY TRAINER Filed Sept. 27, 1941 I sSneets-sh et 1 mikuwsokl Harry E Mikkellsen EMU: (ID (.0

H. E. MIKKELSEN ARTILLERY TRAINER Filed Sept. 27. 1941 Dec. 15,; 19 42.

3 Sheets-Sheet 2 'lill-I I llll-llllll Ju un Hurry E Mikkel sen Patented Dec. 15, 1942 E OFFICE ARTILLERY TRAINER Harry E. Mikkelsen, United States Army, f A

West Point, N. Y.

Application September 27, 1941, Serial No. 412,611

(Granted under the act of March a, 1883, as

amended April so, 1928; 3'1 0. G. 751) 4 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to an artillery trainer firing device. 1

An object of this invention is to provide a pneumatic artillery trainer which requires no expenditure of ammunition.

Another object of this invention is to provide an artillery trainer which requires substantially no cleaning since no powder fouling occurs.

Another object of this invention is to provide an artillery trainer of high accuracy and low dispersion and one which allows a good reproducibility of projectile motion.

Another object of this invention is to provide an artillery trainer which is easy to calibrate and which maintains its calibration during the course of firing the trainer.

Another object of this invention is to provide a pneumatic artillery trainer ,firing device.

which may be easily adjusted for range.

An artillery traineris described in this application that is an improvement over the one described in an article by H. G. Bishop on page 419 of The Military Engineer for, September-October 1933; the gun described in that article is shown in U. S. Patent 2,003,290, Gurney et al., issued June 4, 1935. The apparatus described in this application was designed to overcome disadvantages inherent in the apparatus described in the above mentioned prior art; in actual firing the apparatus described herein is, superior to the prior art apparatus in accuracy, permanency of calibration, ease of cleaning, reproducibility of results, and rapidity of fire.

The specific nature of the invention as Well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which: 7 I

Fig. 1 discloses a schematic view of the pneumatic system in'which the artillery trainer firing device is incorporated.

Fig. 2 is a View in side elevation of a mount for the pneumatic firing device.

Fig. 3 is'a rear elevation of the mount in Fig. 2. v I

Fig. 4 is a perspective view of theassembled pneumatic firing device detached from its mount.

Fig. 5 is a view taken substantially on line 5,5 in Fig. 4 and shows a section through the gun tube with .theprojectile P in firing position. .1

shown Fig. ,6 is a view taken substantially on line 6-6 in Fig. 4 and shows a section through the air chamber, the supporting rod 340 and filling means 34b.

Fig. 7 is a view taken substantially on .line 1-1 in Fig. 4 and shows a section through the quick operating valve. v

Fig. 8 is a View taken substantially on line -88 in Fig. 4 and discloses the manner in which the trigger is mounted on the operating handle of the quick operating valve.

Fig. 9 is a plan view of the quick operating valve. 1

Fig. 10 is a section substantially through the center of the valve and discloses the-manner in which the shaft 40 is connected to the. movable portion of the valve. 1

Fig. 11 discloses a conventional automobile tire check valve (without spring) in the inlet to the gas chamber 34.

Description of the gun mount Referring to the drawings by numeral of reference:

There is provided a bottom carriage I adapted to be bolted or otherwise secured to a base 2 as by the bolts 3. I v

Mounted on the bottom carriage I for rotation about a pintle 4 is a top carriage 5 of any preferred form but herein shown as consisting of side standards -6B, connected at their base by a plate or web 1. Means for traversing the top carriage is provided, a simple form herein shown consisting of a pedestal 8 at the top 0 I which is provided a bearing for a traversing screw 9 which engages in a nut ID on the top carriage. The traversing screw may be operated through means of a handle I I. I

J ournaled in the top carriage by means of the shaft I2 is an angle of "site bracket 13 which may be rocked on said shaft to set in angle of site through means of an angle of site screw l4 suitably journaled at I5 in the top carriage and engaging a nut It on the b-racketa The bracket may be formed with a-rest I! for a gunners quadrant, and with a rearwardly extending arm I8 carrying an index I9 for the elevation scale 20. The bracket terminates at its upper end in a suitable support for a sight2l.

Mounted to rock about the same axis as that of the bracket is a cradle, having a downwardly and rearwardly extending portion 23 in which. is journaled an elevating screw 24 in engagement with a nut 25 on thebracket I3. The elevating screwmay bemconveniently operatedthroughthe "ger 45 is of the pneumatic gun has a free sliding fit. The

gun tube 31 is firmly held by suitable means as by providing a knurled screw 3| which is adapt-" ed to clamp the gun tube 31 at the reduced portive to the valve body at 52 (Fig. 8) and the other end encircling the valve handle 39.. A stop 53 on the fixed plate 46 limits the movement of the trigger 45 and serves to hold the trigger arm 49 in abutting relationship with the handle projection 50. The trigger spring 54 normally holds the trigger against the stop 53 and the. trigger is dis- 7 placed from that position a small amount as the valve handle is rotated bodily to its closed posi-, tion whereby the trigger arm 49 is allowed to fall into the small detent 55 in the handle projection 31a (Fig. 5); shoulders'31b are adapted to cooperate with the screw 31 so as to maintain the gun tube in the mount within a predetermined range. To aid in supporting the gun and to hold' it while adjusting the gun tube 31' to vary it within that predetermined range, an extension 3401 on the gas chamber 34. is l 'ovided toabut one of the side standards 6 along a line contact. Since the extension 34d is cylindrical and since the correspondingly situated side standard 6 has a fiat surface, a line contact between extension 34d and standard 5 must necessarily exist when those two elements abut one another along the length of the extension 34d. The extension 34d is shaped and has such a length that movement of the gun tube a distance between its shoulders 311) will always find the extension 34d in contact with standard 6.

Description of the pneumatic gun The pneumatic gun is made up largely from the following essentialelementsz a gas chamber .34, quick acting valve 35, tube 33, gun tube 31,

serves to hold the gun tube 31 in adjusted position on tube 36. p

The gas chamber 34 has a pneumatic inlet valve stem 34b which may partake the form and size of the conventional automobile tire tube valve stem. A spring'le'ss Shrader valve 346 is disposed F in the valve stem 341) (Fig. '11); A rod 340 is fastened at one'pointon the gas chamber 34 and bent so as to form a straight portion 34d which abuts one of the standards B-on th gun mount along a line contact so that the gun is prevented from rotating in the gun cradle and yet allows an easy movement of the gun along its axial direction as the gun is adjusted in its cradle.

The quick acting valve 35 is of the type where in rotation of its handle 33 through a small angle results in opening or closing the valve. The handle 7 nected to a pivotable closure member 351) through a pin and slot connection 350 between arm 35d on shaft 40 and extension 35c on closure member 35b. The closure member 352) is adapted to open due topressure in the space-35 (Fig. 10).

In order to insure that the valve is opened at the'same rate each timethe gun is fired, a trigpivotally and spring-biased on the plate 46 which has an offset portion 41 held by one of the valve bolts 43. The trigger arm 49 is adapted to abut the projecting portion 50, at 55, on the valve handle ina resilient manner due to the handleispr'ing iLwhich has one end fixed rela- 39 is mounted on shaft 40 which is contion 50.

JIf desired a quick acting magnetically operated valve may be substituted for the mechanical valve shown in the drawings.

[The pneumatic gun is disposed in the pneumatic'system as shown in Fig. 1. In the particular arrangement, compressed air'under a pressure of about 100 lbs. per sq. in. fromtank A is piped to an air regulating valve B which is capable of supplying air at a certain set pressure at all times, provided the pressure in tank A is kept somewhat above lbs. per sq. in. The air regulating valve B is connected to the 'gas chamber 34, which in turn is connected to the gun tube 31 in a manner described'above. Between the gas chamber 34 and the gun tube 31 is the'quick opening valve 35 which, when opened, allows the air under pressure in tank 34 to blow out the projectile P fromthe gun tube 31. lating valve B serves to maintain the pressure in the gas-chamber 34 at a constant value; this valve may partake of a variety of forms and shapes and is used extensively in pneumatic distribution systems. Other gunsjsimilar to the one described, may be supplied from valve B,-as 7 indicated by the dotted lines in Fig.1, when the guns are supposed to constitute an artillery battery.

In order to adjust the range of the gun the following steps are taken:

1. Release the knurled locking ring 33.

2. Loosen screw3l: (Fig. 5.)

3. Rotate gun'tube 31 with respect to tube 36 the required amount and/or slide gun tube 31 in its cradle.

sition.

5. Tighten screw 3|. 1 But for the rod-shaped projections 34d on the gas chamber 34, the gun would inconveniently' rotate. during the above adjustment operation; the projection 3401 makes a line contact with the standard 6 so that the gun may be bodily moved .in its cradle without imparting any rotation to the gun. Besides being convenient inallowing an adjustment to be made with one hand, this feature is important because the gunis moved only in one of the three dimensions and thus-allows the gun to be sightedrather quickly. r' I p The unit shown in Fig. 4 may have its range between the free end or muzzle of, the gun tube 31 and the end of tube 36 upon 'which j'the ball projectile P isadapted to rest; thatflvolum'eyis changed by simply unlocking ,ring33 and turning gun tube 31 with respect .to, tube 33." i

' I claim:

l. A unit adapted to 'fireproj'ectiles p re detei -mined fractions of'the-ranges of pieces of standard artillery for training an artillery gun' 'c'r'w-- The air regu 4. Rotate the locking ring 38 into locking p0 embodying a gas chamber, a tube, a quick acting valve joining the chamber and the tube, said tube having its free end adapted to abut against a ball projectile whereby the free end is sealed, a gun tube coaxially mounted on the tube, means for adjusting the relative position of the gun tube and tube, means for locking the tubes in adjusted position; a gun mount embodying a hollow portion adapted to snugly receive the gun tube, said gun tube having a grooved surface, a screw threaded in the gun mount and projecting into said grooved surface, said screw serving as a combination stop and lock element for movement of the gun tube.

2. A unit adapted to fire projectiles predetermined fractions of ranges of pieces of standard artillery for training an artillery gun crew embodying a gas chamber, a tube, a quick acting valve joining the chamber and the tube, a gun tube coaxially mounted on the tube, said chamber, tube, valve and gun tube disposed in a U shape, said gun tube having a cylindrical outer surface adapted to receive a clamp, a projection on the gas chamber; and a support having a clamp for said gun tube cylindrical outer surface and having a flat surface for engagement of said projection along a line contact.

3. A U-shaped unit adapted to fire projectiles predetermined fractions of ranges of pieces of standard artillery for training an artillery gun crew embodying a gas chamber forming one of the parallel legs of the U, a tube, a gun tube coaxially mounted on the tube, said tube and gun tube forming the other parallel leg of the U, a quick acting valve joining the chamber and the tube and forming the horizontal portion of the U, an operating handle for the valve projecting beyond the confines of the U, said gun tube having a cylindrical clamping surface, and a projec tion on the gas chamber adapted to make contact with a support along a lin parallel to the parallel legs of the U.

4. In combination, a gun mount embodying a base, a top carriage on the base, a cradle carried by the top carriage, a gun support on the cradle, a U-shaped gun having a cylindrical clamping surface on one of the parallel legs of the U and having a cylindrical projection on the other parallel leg of the U, said top carriage having an outer flat surface extending vertically and parale lel to the parallel legs of the U, means for clamping the cylindrical clamping surface in the gun support, and said cylindrical projection making a line contact with the flat carriage surface.

HARRY E. MIKKELSEN. 

